Device for the production of bags



May 11, 1965 A. EGLl DEVICE FOR THE PRODUCTION OF BAGS Filed June 19,1963 United States Patent 1 Claim: c1. 93 12 The patent applicationSerial No. 48,944 filed on August 11, 1960 by Alwin Egli relates to amethod for the production of bags from sheets cut to size as well as toa device for carrying out this method.

According to said patent application the device which comprises at leasttwo main mandrels for the folding and interwelding of the bottom of thebags which are capable of being swung stepwise into various operativepositions, is characterised by an auxiliary mandrel co-operating withthe main mandrels and axially adjustable relative to the same with whichare associated a folding box for the formation of the hose for the bagsand heatable clamping and welding jaws for the formation of thelongitudinal seam, and by feeder rollers for transferring the hose forthe bags from the auxiliary mandrel to the main mandrel.

The invention has the object of providing an improvement of the devicedescribed in said patent application. It has been found that whenworking comparatively thin sheets e.g. foils of synthetic substances,into bags the transfer of the hose for the bags from the auxiliarymandrel to the main mandrel by means of the feeder rollers gives rise tobreak down. Since the hoses for the bags were pulled off by the rollersfrom the auxiliary mandrel but were pushed upon the main mandrels thecase could arise in which they were set up on the main mandrels if theyhad not sumcient inherent stiffness. This disadvantage is to be overcomeby the present invention.

With this and other objects in view which will become apparent from thefollowing description and accompanying drawings, I provide a device forthe production of bags from sheets cut to size having at least on itsmargins to be interwelded a surface consisting of thermo-plasticmaterial, comprising in combination: two main mandrels arranged forbeing swung step-wise into various operative positions for the foldingand interwelding of the bag bottoms, an auxiliary mandrel co-operatingwith said main mandrels and axially adjustable relative to the same,said auxiliary mandrel having a folding box for the formation of thehose bag and heatable clamping and welding jaws for the formation of thelongitudinal seam of the said hose bag, a pair of tongs longitudinallymovable in a 1ongitudinal groove of said main mandrels for the transferof the hose bag from said auxiliary mandrel to said main mandrel.

These and other features of my said invention will be clearly understoodfrom the following description of a preferred embodiment thereof givenby way of example with reference to the accompanying drawing, which isdiagrammatic side elevation of a device according to the invention.

On an arm 1 rigidly connected with the machine frame two bars 2, 3, arerigidly attached. On the bar 2 an auxiliary mandrel 4 is mounted axiallyslidable. Its displacement is effected by the turning of a lever 5 whichis connected by a connecting rod 6 with the auxiliary mandrel 4, thedisplacement being effected in the working rhythm of the machine. On thebar 3 two rocking levers 7, 8, are mounted which at their ends carryheatable jaws 9, which serve for the production of the longitudinal seamof the hose bag. The jaws 9 are heated in the usual manner electrically.

Below the auxiliary mandrel 4 a folding box 10 is arice ranged which ismounted vertically slidable on columns 11. It forms on its top a tablewhich serves for receiving the sheets 12 from which the bag is to beproduced. For the supply of the sheets 12 pairs of rollers 13 areprovided. The folding box 10 is so constructed that in its uppermostposition it can embrace the auxiliary mandrel 4 from three sides. Thesheet 12 lying on top of the folding box 10 is folded around theauxiliary mandrel 4 when the folding box is moved to its uppermost endposition. The longitudinal edges produced on top beyond the auxiliarymandrel and the folding box are then engaged by the heating jaws 9 andinterwelded whereby the hose bag is formed.

On a vertical axle 14 a mandrel wheel 15, having for example four mainmandrels 16, is arranged of which one is illustrated in elevation. Themain mandrel 16 illustrated lies in axial alignment with the auxiliarymandrel 4, i.e. in the position in which the transfer of the hose bag 12from the auxiliary mandrel to the main mandrel takes place. The lowerwall 16a of the main mandrel is tiltable about an axle 17 in order tofacilitate the fitting of the hose bag on it. The swinging-in of thewall 16a is effected automatically when the main mandrel 16 runs intothe working position illustrated thereby that a roller 18 arranged onthe lower wall 16a runs on a fixed guide rail 19. On top of the mainmandrel 16 is moreover arranged a press jaw 20, which is mounted on arocker arm 21 pivotable about an axle 22 which arm co-operates with alever 23 actuated by the main drive of the machine. The press jaw 20serves for arresting the hose bag transferred to the main mandrel 16. V

For the transfer of the hose bag from the auxiliary mandrel to the mainmandrel a pair of tongs is provided. The same are mounted on a tongsslide 25 which is slidably mounted on two bars 26 arranged parallel tothe main mandrel 16. The tongs slide 25 is moved to-andfro by means of alever 27 connected to the main drive of the machine by means of aconnecting rod 28. The tongs 24 engage into a longitudinal groove 29 ofthe main mandrel 16. The auxiliary mandrel 4 has likewise acorresponding groove at the end adjacent the main mandrel 16. The upperjaw of the tongs 24 is rigidly connected with the tongs slide 25. Thelower jaw is, however, pivotably mounted on the tongs slide 25 and isconnected with a lever 30 which co-operates at its lower end with thedrop surface of an opener rail 31. A spring 33 tends to pull the lowerjaw of the tongs into its closed position. The opener rail 31 ispivotably mounted on two parallel levers 32 which in turn are connectedin a manner not illustrated with the main drive of the machine. Byturning the lever 32 the opener rail 31 is raised parallel to itself, orlowered. By raising the opener rail accordingly the tongs 24 are opened,and by lowering the opener rail the tongs are again closed by the spring33, independently of the position of the tong slide 25.

For transferring the hose bag 12' the auxiliary mandrel is firstly movedtowards the main mandrel 16 by turning the lever 5. Thereafter theopener rail 31 is raised into its upper position so that the tongs 24are opened. At the same time by means of the lever 27 the tongs slide 25is shifted to the left-hand side into the position illustrated in chaindotted lines in which the margin of the hose bag 12 engages between theopen jaws of the tongs 24. The opener rail 31 is then lowered so thatthe tongs 24 close, and clamp the hose bag fast. Then the tongs slide ismoved towards the right again into its original position whereby thetongs 24 transfer the hose bag 12' to the main mandrel. When the hosebag abuts an abutment 34, the opener rail is again raised so that thetongs 24 release the hose bag and the jaws moved out of the same. Thenthe press jaw 20 is lowered and the mandrel wheel is turned into thenext working position in which the further folding operations of thehose bag, i.e. the folding of the bottom of the bag are carried out.

Instead of a pair of tongs 24 two simultaneously operating tongs may bearranged side by side.

While I have described herein and illustrated in the accompanyingdrawing what may be considered a typical and particularly usefulembodiment of my invention I Wish it to be understood that I do notlimit myself to the particular details and dimensions described andillustrated; for obvious modifications will occur to a person skilled inthe art.

What I claim as my invention and desire to secure by Letters Patent, is;i

A device for the production of bags of sheet blanks cut to size havingat least on its margins to be interwelded a surface consisting ofthermo-plastic material, comprising in combination: two main mandrelsarranged for being stepwise rotated nto various operative positions forthe folding and interwelding of the bag bottoms, an auxiliary mandrelcooperating with said main mandrels and axially adjustable relative tothe same, said auxiliary mandrel having a folding box for the formationof the hose bag, and heatable clamping and welding jaws, a pair of tongslongitudinally movable in a longitudinal groove of one of said mainmandrels for the transfer of the hose bag from said auxiliary mandrel tosaid main mandrel, an opener rail movable parallel to itself in avertical direction, a tong slide movable in a direction parallel withsaid longitudinal groove, said pair of tongs being supported by saidtong slide, and having jaws one of which is pivotally mounted on saidtong slide, the other of said jaws being fixedly connected with saidtong slide, a lever connected to said pivoted jaw of said tongs, saidopener rail cooperating With said lever so that when the same is movedin parallelism said opener iai win pivot said lever and jaw connectedtherewith to move the same away from said fixed lever and open saidtongs independent of the position of said tongs slide.

References Cited by the Examiner UNITED STATES PATENTS 6/58 Triolo 9344.1 x 4/63 Egli 93 12

